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CnC_Renegade/Code/ww3d2/colorspace.h

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C

/*
** Command & Conquer Renegade(tm)
** Copyright 2025 Electronic Arts Inc.
**
** This program is free software: you can redistribute it and/or modify
** it under the terms of the GNU General Public License as published by
** the Free Software Foundation, either version 3 of the License, or
** (at your option) any later version.
**
** This program is distributed in the hope that it will be useful,
** but WITHOUT ANY WARRANTY; without even the implied warranty of
** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
** GNU General Public License for more details.
**
** You should have received a copy of the GNU General Public License
** along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
/***********************************************************************************************
*** C O N F I D E N T I A L --- W E S T W O O D S T U D I O S ***
***********************************************************************************************
* *
* Project Name : Colorspace *
* *
* $Archive:: /VSS_Sync/ww3d2/colorspace.h $*
* *
* Original Author:: Hector Yee *
* *
* $Author:: Vss_sync $*
* *
* $Modtime:: 8/29/01 9:50p $*
* *
* $Revision:: 1 $*
* *
*---------------------------------------------------------------------------------------------*
* Functions: *
* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
#if defined(_MSC_VER)
#pragma once
#endif
#ifndef COLORSPACE_H
#define COLORSPACE_H
#include <wwmath.h>
void RGB_To_HSV(Vector3 &hsv,const Vector3 &rgb);
void HSV_To_RGB(Vector3 &rgb, const Vector3 &hsv);
void Recolor(Vector3 &rgb, const Vector3 &hsv_shift);
//---------------------------------------------------------------------
// Color Conversions
//---------------------------------------------------------------------
inline void RGB_To_HSV(Vector3 &hsv,const Vector3 &rgb)
// modified from Foley et al. page 592
// converts rgb[0..1] to h [0,360), s and v in [0,1]
// negative h values are to signify undefined
{
float max=WWMath::Max(rgb.X,rgb.Y);
max=WWMath::Max(max,rgb.Z);
float min=WWMath::Min(rgb.X,rgb.Y);
min=WWMath::Min(min,rgb.Z);
// value
hsv.Z=max;
// saturation
hsv.Y=(max!=0.0f)?((max-min)/max):0.0f;
if (hsv.Y==0.0f) hsv.X=-1.0f;
else
{
float delta=max-min;
if (rgb.X==max)
hsv.X=(rgb.Y-rgb.Z)/delta;
else if (rgb.Y==max)
hsv.X=2.0f+ (rgb.Z-rgb.X)/delta;
else if (rgb.Z==max)
hsv.X=4.0f+ (rgb.X-rgb.Y)/delta;
hsv.X*=60.0f;
if (hsv.X<0.0f) hsv.X+=360.0f;
}
}
inline void HSV_To_RGB(Vector3 &rgb, const Vector3 &hsv)
{
float h=hsv.X;
float s=hsv.Y;
float v=hsv.Z;
if (hsv.Y==0.0f) {
rgb.Set(v,v,v);
} else {
float f,p,q,t;
int i;
if (h==360.0f) h=0.0f;
h/=60.0f;
i=WWMath::Floor(h);
f=h-i;
p=v*(1.0f-s);
q=v*(1.0f-(s*f));
t=v*(1.0f-(s*(1.0f-f)));
switch (i) {
case 0:
rgb.Set(v,t,p);
break;
case 1:
rgb.Set(q,v,p);
break;
case 2:
rgb.Set(p,v,t);
break;
case 3:
rgb.Set(p,q,v);
break;
case 4:
rgb.Set(t,p,v);
break;
case 5:
rgb.Set(v,p,q);
break;
}
}
}
inline void Recolor(Vector3 &rgb, const Vector3 &hsv_shift)
{
Vector3 hsv;
RGB_To_HSV(hsv,rgb);
// If the Hue has the "undefined flag" (a negative value), this means that the color is pure
// monochrome. In this case do not shift the hue (it is undefined) or the saturation (it is 0
// so it cannot be decreased, and increasing it would cause the undefined hue to actually
// become visible). In this case, we only modify the value.
if (hsv.X<0.0f) hsv+=Vector3(0.0f,0.0f,hsv_shift.Z);
else hsv+=hsv_shift;
// angular mod
if (hsv.X<0.0f) hsv.X+=360.0f;
if (hsv.X>360.0f) hsv.X-=360.0f;
// clamp saturation and value
hsv.Y=WWMath::Clamp(hsv.Y,0.0f,1.0f);
hsv.Z=WWMath::Clamp(hsv.Z,0.0f,1.0f);
HSV_To_RGB(rgb,hsv);
}
#endif